Processes for producing acrylic acids and acrylates

Abstract

In one embodiment, the invention is to a process for producing an acrylate product. The process comprises the step of providing a crude product stream comprising the acrylate product and an alkylenating agent. The process further comprises the step of separating at least a portion of the crude product stream to form an alkylenating agent stream and an intermediate product stream. The alkylenating agent stream comprises at least 1 wt % alkylenating agent and the intermediate product stream comprises acrylate product.

We claim: 
     
       1. A process for producing an acrylate product, the process comprising the steps of:
 (a) reacting an alkanoic acid comprising acetic acid and an alkylenating agent to form a crude product stream comprising the acrylate product comprising from 5 wt % to 50 wt % acrylic acid, from 0.5 wt % to 50 wt % alkylenating agent comprising formaldehyde and/or precursors thereof, from 5 wt % to 50 wt % acetic acid, and from 1 wt % to 60 wt % water; 
 (b) condensing at least a portion of the crude product stream to form a condensed crude product stream; and 
 (c) separating at least a portion of the condensed crude product stream to form an alkylenating agent stream comprising at least 1 wt % alkylenating agent and an intermediate acrylate product stream comprising acrylic acid and acetic acid. 
 
     
     
       2. The process of  claim 1 , further comprising the step of:
 (d) separating the intermediate acrylate product stream to form a finished acrylate product stream comprising at least 85 wt % acrylic acid and a first finished acetic acid stream comprising from 50 wt % to 99.9 wt % acetic acid. 
 
     
     
       3. The process of  claim 2 , wherein step (d) is performed in at least one column and/or step (c) is performed in a two column system. 
     
     
       4. The process of  claim 2 , wherein step (d) is performed via azeotropic distillation. 
     
     
       5. The process of  claim 2 , wherein step (d) is performed in at least two columns, each of which has less than 10 theoretical trays. 
     
     
       6. The process of  claim 2 , wherein at least a portion of the first finished acetic acid stream is recycled to the reactor. 
     
     
       7. The process of  claim 1 , further comprising the step of:
 separating the alkylenating agent stream to form a purified alkylenating stream comprising at least 1 wt % alkylenating agent. 
 
     
     
       8. The process of  claim 7 , wherein the separating is performed in at least one column. 
     
     
       9. The process of  claim 7 , wherein at least a portion of the purified alkylenating agent stream is recycled to the reactor. 
     
     
       10. The process of  claim 2 , further comprising the step of:
 separating the intermediate acrylate product stream to form the finished acrylate product stream, the first finished acetic acid stream, a second finished acetic acid stream and a water stream. 
 
     
     
       11. The process of  claim 10 , wherein the separating is performed in at least one column. 
     
     
       12. The process of  claim 10 , wherein the separating is performed via azeotropic distillation. 
     
     
       13. The process of  claim 10 , wherein at least a portion of the second finished acetic acid stream is recycled to the reactor. 
     
     
       14. The process of  claim 1 , wherein the alkylenating agent stream comprises at least 5 wt % alkylenating agent. 
     
     
       15. The process of  claim 1 , wherein the intermediate acrylate product stream comprises at least 5% wt % acrylic acid. 
     
     
       16. The process of  claim 1 , wherein the intermediate acrylate product stream further comprises less than 25 wt % water and less than 95 wt % acetic acid. 
     
     
       17. The process of  claim 1 , wherein step (c) is performed in at least one column. 
     
     
       18. The process of  claim 1 , wherein step (c) is performed in a two column system. 
     
     
       19. A process for producing an acrylate product, the process comprising the steps of:
 (a) reacting an alkanoic acid comprising acetic acid and an alkylenating agent to form a crude product stream comprising the acrylate product comprising from 5 wt % to 50 wt % acrylic acid, from 0.5 wt % to 50 wt % alkylenating agent comprising formaldehyde and/or precursors thereof, from 5 wt % to 50 wt % acetic acid, and from 1 wt % to 60 wt % water; 
 (b) separating at least a portion of the crude product stream to form an alkylenating agent stream comprising at least 1 wt % alkylenating agent and an intermediate acrylate product stream comprising acrylic acid and acetic acid; and 
 (c) separating the intermediate acrylate product stream to form a finished acrylate product stream comprising at least 85 wt % acrylic acid and a first finished acetic acid stream comprising from 50 wt % to 99.9 wt % acetic acid. 
 
     
     
       20. The process of  claim 19 , wherein step (b) comprises condensing the crude product stream and separating the condensed crude product stream to form the alkylenating agent stream and the intermediate acrylate product stream. 
     
     
       21. The process of  claim 1 , wherein the crude product stream further comprises propionic acid. 
     
     
       22. The process of  claim 19 , wherein the crude product stream further comprises propionic acid.